Desorption transient time dependence

The time dependence of reductive desorption was explored by single potential step experiments (from E to E ), Selected transients (dotted lines) for freshly prepared BP3 monolayers on Au(lll)-(1 x 1)/0.1 M NaOH are displayed in Fig. 2IB. The traces are characterized by an initial exponential decay t <5 ms, q<5 iC cm ), followed by a well-developed maximum, /max at fmax) which increases and shifts towards shorter times with more nega-... 

For high solubility penetrants, great complexity is often observed in sorption-desorption kinetics or transient permeation due to time-dependent rearrangements of crystalline regions in response to swelling-induced stresses (59,60). These... 

Thus, the most suitable route for obtaining information on the adsorption/desorption kinetics is from the short-time transient behavior. Under these conditions, surface diffusion effects are negligible and the short-time current response depends only on Ka, Kd, and A for a given tip/substrate separation. Provided that an independent measurement of A can be made, an absolute assignment of the interfacial kinetics is possible. Furthermore, analysis of the long-time current allows the importance, and magnitude, of surface diffusion to be determined. 

The above experiments on monolayers illustrate the strong dependence of desorption rates on n. In real systems stabilised by proteins, n for the film on average does not exceed a particular maximum value at which the rate of adsorption from solution is balanced by the rate of desorption. On perturbation from the equilibrium state of the film, such as a transient (local) expansion or compression a knowledge of both rates is important. Unfortunately, measurements of adsorption rates are not so straightforward since the surface concentration of protein, r, must be monitored with time and is not predetermined as in the spread monolayers. There is often disagreement between adsorption kinetic results obtained via different techniques - see below, for example. Relatively few measurements have been made of the adsorption kinetics of S-lactoglobulin at the A-W interface and for all proteins, because of experimental difficulties, there seem to be almost no direct measurements of r t) at O-W interfaces. 

To model the desorption-behavior of Oxygen in dependence of pretreatment time and temperature, a FEM analysis was performed. The shape of the resin was determined by optical analysis. The transient state of diflusion could be modeled using COSMOS Works by modeling the transient thermal conduction since both problems show a similar differential equation - (2) and (5) ... 

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